PNG ICO ICNS MORE
Avatars & smileys
3D
Free Large Boss Icon Set
shield, Protection, police
Black
512x512
stupid, strong, power
shiled, stupid, strong
knight, horseman, king
Photography & graphic design
32x32 Free Design Icons
locked, Key, secure
32x32
Key, password, login
Gaming & gambling
Photorealistic
48x48 Free Object Icons
locked, Hide, login
48x48
security, privacy, Restriction
private, Protection, security
Antivirus, Guard, Army
Unlock, Safe, secure
Protection, Close, Safe
Khaki
security, Lock, secure
Unlock, Key, locked
Network & communications
Pixel
16x16 Free Application Icons
secure, Log in, pass
16x16
Key, Log in, login
Lock, security, pwd
Business & finance
Glyph
Devine Icons Part 2
security
128x128
Desktop apps
Ourea Icons
256x256
UI
Flat
Metro UI Icon Set
microsoft, security, Essentials
CornflowerBlue
Approved, security
ForestGreen
security, denied
Crimson
RoyalBlue
SEO & web
Metro Uinvert Dock